Multi-Currency does not have the ability to convert currencies within the Shopify checkout by itself.
Due to security concerns, Shopify doesn't provide access for third-party developers to change elements of their checkout process. This means that you are only able to set one default currency to process payments with on a Shopify store.
If you have Bold Cashier installed on your store, Multi-Currency has a direct integration with this app to provide your customers with the flexibility to pay in their desired currency. Cashier uses its own payment gateway providers to accept payments for orders in currencies that are not the store's default.
Caution
At this time, Bold Cashier is unavailable for installation via Shopify. This is due to the re-evaluations and restrictions created on payments being processed by third-party checkouts on their platform. If your store has installed our Bold Cashier app prior to January 20th, 2020 - you will be able to continue using this app as it is grandfathered on your store.
As of February 19, 2021, Bold Multi-Currency is no longer available to install on the Shopify App Store. If your store has installed our Bold Multi-Currency app prior to February 19, 2021 - you will be able to continue using this app as it is grandfathered on your store.